Lactose is a great binder / filler because of its compressibility, flow and high solubility. Lactose is widely used as a filler or diluent in tablets, capsules, and in lyophilized products and infant feed formulas. Usually, fine grades of lactose are used in the preparation of tablets by the wet granulation method or when milling during processing is carried out, since the fine size permits better mixing with other formulation ingredients and utilizes the binder more efficiently. Lactose tends to be the most optimal filler for capsule type products.